Refactor watchdog logic to implement host-based delay in watchdog_run function

src/commandline.sh

@@ -200,6 +200,6 @@ parse_commandline_args() {
 	if [ "$WATCHDOGMODE" = "true" ]; then
 		startup_version
 		startup_debug
-		watchdog_check
+		watchdog_run
 	fi
 }

src/logic_watchdog.sh

@@ -160,6 +160,15 @@ get_watchdog_status() {
 
 }
 
+watchdog_run() {
+	local host_hash
+	host_hash=$(printf '%s' "$(hostname)" | md5sum | awk '{print $1}' | cut -c1-8 | xargs printf '%d' 16 16)
+	local offset=$(( host_hash % 300 ))
+	echo "Watchdog delay: sleeping ${offset}s (host-based offset)"
+	sleep "$offset"
+	watchdog_check
+}
+
 watchdog_check() {
 	echo "---------------------------"
 	echo " Nightscout Watchdog mode"